Michereff M F F, Borges M, Aquino M F S, Laumann R A, Mendes Gomes A C M, Blassioli-Moraes M C
Embrapa Recursos Genéticos e Biotecnologia (Cenargen),Brasília,Brazil.
Bull Entomol Res. 2016 Oct;106(5):663-71. doi: 10.1017/S0007485316000419. Epub 2016 Jun 14.
During host selection, physical and chemical stimuli provide important cues that modify search behaviours of natural enemies. We evaluated the influence of volatiles released by eggs and egg extracts of the stink bug Euschistus heros and by soybean plants treated with the eggs and egg extracts on Telenomus podisi foraging behaviour. Responses to volatiles were evaluated in Y-tube olfactometers after exposure to (1) one egg cluster for 24 h; (2) plants with eggs laid by the stink bug, tested at 24, 48, and 72 h after treatment; (3) plants with eggs laid artificially, tested at 24, 48, and 72 h after treatment; and (4) plants treated with acetone or hexane extracts of eggs. Telenomus podisi was attracted to volatiles emitted by one egg cluster and to acetone extracts of one egg cluster, but not to air or acetone controls. There were no responses to odours of plants treated with eggs or egg extracts. Analysis of acetone extracts of egg clusters by gas chromatography revealed the major components were saturated and unsaturated fatty acids, including hexadecanoic acid, linoleic acid, and (Z)-9-octadecenoic acid. Our results suggest that one egg cluster and the acetone extract of one egg cluster contain volatile compounds that can modify T. podisi foraging behaviour, and that the amounts of these compounds, probably together with some minor compounds, are important for host recognition by T. podisi. Also, the oviposition damage or egg extracts on the plant did not elicit indirect defences that attracted Telenomus podisi.
在寄主选择过程中，物理和化学刺激提供了重要线索，可改变天敌的搜索行为。我们评估了绿蝽Euschistus heros的卵和卵提取物释放的挥发物以及用这些卵和卵提取物处理过的大豆植株对豆荚广肩小蜂觅食行为的影响。在Y型嗅觉仪中，分别在暴露于以下物质后评估对挥发物的反应：(1) 一个卵块24小时；(2) 有绿蝽产卵的植株，在处理后24、48和72小时进行测试；(3) 人工产卵的植株，在处理后24、48和72小时进行测试；以及(4) 用卵的丙酮或己烷提取物处理过的植株。豆荚广肩小蜂被一个卵块释放的挥发物和一个卵块的丙酮提取物所吸引，但对空气或丙酮对照无反应。对用卵或卵提取物处理过的植株气味没有反应。通过气相色谱分析卵块的丙酮提取物发现，主要成分是饱和脂肪酸和不饱和脂肪酸，包括十六烷酸、亚油酸和(Z)-9-十八碳烯酸。我们的结果表明，一个卵块和一个卵块的丙酮提取物含有可改变豆荚广肩小蜂觅食行为的挥发性化合物，并且这些化合物的量，可能连同一些次要化合物，对豆荚广肩小蜂识别寄主很重要。此外，植株上的产卵损伤或卵提取物并未引发吸引豆荚广肩小蜂的间接防御反应。
